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2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-311717

ABSTRACT

The Coronavirus Disease of 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global public health and economy. Therapeutic options such as monoclonal antibodies (mAbs) against SARS-CoV-2 are in urgent need. We have identified potent monoclonal antibodies binding to SARS-CoV-2 Spike protein from COVID-19 convalescent patients and one of these antibodies, P4A1, interacts directly and covers the majority of the Receptor Binding Motif (RBM) of Spike receptor-binding domain (RBD), shown by high-resolution complex structure analysis. We further demonstrated P4A1 binding and neutralizing activities against wild type and mutant spike proteins. P4A1 was subsequently engineered to reduce the potential risk for antibody-dependent enhancement (ADE) of infection and to extend its half-life. The engineered mAb exhibits optimized pharmacokinetic and safety profile, and results in complete viral clearance in a rhesus monkey model of COVID-19 following a single injection.

4.
Cell Discov ; 7(1): 82, 2021 Sep 07.
Article in English | MEDLINE | ID: covidwho-1397862

ABSTRACT

The pandemic of COVID-19 caused by SARS-CoV-2 has raised a new challenges to the scientific and industrious fields after over 1-year spread across different countries. The ultimate approach to end the pandemic is the timely application of vaccines to achieve herd immunity. Here, a novel SARS-CoV-2 receptor-binding domain (RBD) homodimer was developed as a SARS-CoV-2 vaccine candidate. Formulated with aluminum adjuvant, RBD dimer elicited strong immune response in both rodents and non-human primates, and protected mice from SARS-CoV-2 challenge with significantly reducing viral load and alleviating pathological injury in the lung. In the non-human primates, the vaccine could prevent majority of the animals from SARS-CoV-2 infection in the respiratory tract and reduce lung damage. In addition, antibodies elicited by this vaccine candidate showed cross-neutralization activities to SARS-CoV-2 variants. Furthermore, with our expression system, we provided a high-yield RBD homodimer vaccine without additional biosafety or special transport device supports. Thus, it may serve as a safe, effective, and low-cost SARS-CoV-2 vaccine candidate.

5.
MAbs ; 13(1): 1930636, 2021.
Article in English | MEDLINE | ID: covidwho-1258715

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease-2019 (COVID-19), interacts with the host cell receptor angiotensin-converting enzyme 2 (hACE2) via its spike 1 protein during infection. After the virus sequence was published, we identified two potent antibodies against the SARS-CoV-2 receptor binding domain (RBD) from antibody libraries using a phage-to-yeast (PtY) display platform in only 10 days. Our lead antibody JMB2002, now in a Phase 1 clinical trial (ChiCTR2100042150), showed broad-spectrum in vitro blocking activity against hACE2 binding to the RBD of multiple SARS-CoV-2 variants, including B.1.351 that was reportedly much more resistant to neutralization by convalescent plasma, vaccine sera and some clinical-stage neutralizing antibodies. Furthermore, JMB2002 has demonstrated complete prophylactic and potent therapeutic efficacy in a rhesus macaque disease model. Prophylactic and therapeutic countermeasure intervention of SARS-CoV-2 using JMB2002 would likely slow down the transmission of currently emerged SARS-CoV-2 variants and result in more efficient control of the COVID-19 pandemic.


Subject(s)
Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Antibodies, Neutralizing/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , COVID-19/prevention & control , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Antibody Specificity , Binding Sites, Antibody , CHO Cells , COVID-19/immunology , COVID-19/metabolism , COVID-19/virology , Chlorocebus aethiops , Cricetulus , Disease Models, Animal , Epitopes , Macaca mulatta , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Vero Cells
6.
Nat Commun ; 12(1): 2623, 2021 05 11.
Article in English | MEDLINE | ID: covidwho-1225506

ABSTRACT

COVID-19 pandemic caused by SARS-CoV-2 constitutes a global public health crisis with enormous economic consequences. Monoclonal antibodies against SARS-CoV-2 can provide an important treatment option to fight COVID-19, especially for the most vulnerable populations. In this work, potent antibodies binding to SARS-CoV-2 Spike protein were identified from COVID-19 convalescent patients. Among them, P4A1 interacts directly with and covers majority of the Receptor Binding Motif of the Spike Receptor-Binding Domain, shown by high-resolution complex structure analysis. We further demonstrate the binding and neutralizing activities of P4A1 against wild type and mutant Spike proteins or pseudoviruses. P4A1 was subsequently engineered to reduce the potential risk for Antibody-Dependent Enhancement of infection and to extend its half-life. The engineered antibody exhibits an optimized pharmacokinetic and safety profile, and it results in complete viral clearance in a rhesus monkey model of COVID-19 following a single injection. These data suggest its potential against SARS-CoV-2 related diseases.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Monoclonal/metabolism , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , Antibody Specificity/immunology , COVID-19/drug therapy , COVID-19/epidemiology , Cell Line, Tumor , Cells, Cultured , Chlorocebus aethiops , Female , Humans , Macaca mulatta , Male , Mutation , Pandemics , Protein Binding , Protein Domains , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Treatment Outcome , Vero Cells
7.
Virol Sin ; 36(5): 879-889, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1174014

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/prevention & control , Mice , Mice, Transgenic , Primates , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Inactivated/immunology
8.
Cell Res ; 31(2): 126-140, 2021 02.
Article in English | MEDLINE | ID: covidwho-1015005

ABSTRACT

The current coronavirus disease 2019 (COVID-19) pandemic presents a global public health challenge. The viral pathogen responsible, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), binds to the host receptor ACE2 through its spike (S) glycoprotein, which mediates membrane fusion and viral entry. Although the role of ACE2 as a receptor for SARS-CoV-2 is clear, studies have shown that ACE2 expression is extremely low in various human tissues, especially in the respiratory tract. Thus, other host receptors and/or co-receptors that promote the entry of SARS-CoV-2 into cells of the respiratory system may exist. In this study, we found that the tyrosine-protein kinase receptor UFO (AXL) specifically interacts with the N-terminal domain of SARS-CoV-2 S. Using both a SARS-CoV-2 virus pseudotype and authentic SARS-CoV-2, we found that overexpression of AXL in HEK293T cells promotes SARS-CoV-2 entry as efficiently as overexpression of ACE2, while knocking out AXL significantly reduces SARS-CoV-2 infection in H1299 pulmonary cells and in human primary lung epithelial cells. Soluble human recombinant AXL blocks SARS-CoV-2 infection in cells expressing high levels of AXL. The AXL expression level is well correlated with SARS-CoV-2 S level in bronchoalveolar lavage fluid cells from COVID-19 patients. Taken together, our findings suggest that AXL is a novel candidate receptor for SARS-CoV-2 which may play an important role in promoting viral infection of the human respiratory system and indicate that it is a potential target for future clinical intervention strategies.


Subject(s)
COVID-19/metabolism , Proto-Oncogene Proteins/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Respiratory Mucosa/cytology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Bronchi/cytology , Bronchi/metabolism , Cell Line , Humans , Lung/cytology , Lung/metabolism , Models, Molecular , Protein Interaction Domains and Motifs , Proto-Oncogene Proteins/analysis , Receptor Protein-Tyrosine Kinases/analysis , Respiratory Mucosa/metabolism , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/analysis , Virus Internalization
9.
Emerg Microbes Infect ; 9(1): 2606-2618, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-944152

ABSTRACT

The ongoing COVID-19 pandemic is causing huge impact on health, life, and global economy, which is characterized by rapid spreading of SARS-CoV-2, high number of confirmed cases and a fatality/case rate worldwide reported by WHO. The most effective intervention measure will be to develop safe and effective vaccines to protect the population from the disease and limit the spread of the virus. An inactivated, whole virus vaccine candidate of SARS-CoV-2 has been developed by Wuhan Institute of Biological Products and Wuhan Institute of Virology. The low toxicity, immunogenicity, and immune persistence were investigated in preclinical studies using seven different species of animals. The results showed that the vaccine candidate was well tolerated and stimulated high levels of specific IgG and neutralizing antibodies. Low or no toxicity in three species of animals was also demonstrated in preclinical study of the vaccine candidate. Biochemical analysis of structural proteins and purity analysis were performed. The inactivated, whole virion vaccine was characterized with safe double-inactivation, no use of DNases and high purity. Dosages, boosting times, adjuvants, and immunization schedules were shown to be important for stimulating a strong humoral immune response in animals tested. Preliminary observation in ongoing phase I and II clinical trials of the vaccine candidate in Wuzhi County, Henan Province, showed that the vaccine is well tolerant. The results were characterized by very low proportion and low degree of side effects, high levels of neutralizing antibodies, and seroconversion. These results consistent with the results obtained from preclinical data on the safety.


Subject(s)
COVID-19 Vaccines/immunology , SARS-CoV-2 , Animals , Antibodies, Viral , COVID-19 Vaccines/adverse effects , Female , Immunity, Humoral , Male , Vaccines, Inactivated/adverse effects , Vaccines, Inactivated/immunology
10.
Nat Commun ; 11(1): 5752, 2020 11 13.
Article in English | MEDLINE | ID: covidwho-926678

ABSTRACT

Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antiviral Agents/pharmacology , Betacoronavirus/immunology , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Viral/immunology , COVID-19 , Cell Line , Chlorocebus aethiops , Coronavirus Infections/prevention & control , Female , HEK293 Cells , Humans , Macaca mulatta , Male , Pandemics/prevention & control , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/prevention & control , Receptors, IgG/genetics , Receptors, IgG/immunology , Receptors, Virus/metabolism , SARS-CoV-2 , Vero Cells , Virus Attachment
11.
Antiviral Res ; 182: 104874, 2020 10.
Article in English | MEDLINE | ID: covidwho-891945

ABSTRACT

Based on genome-scale loss-of-function screens we discovered that Topoisomerase III-ß (TOP3B), a human topoisomerase that acts on DNA and RNA, is required for yellow fever virus and dengue virus-2 replication. Remarkably, we found that TOP3B is required for efficient replication of all positive-sense-single stranded RNA viruses tested, including SARS-CoV-2. While there are no drugs that specifically inhibit this topoisomerase, we posit that TOP3B is an attractive anti-viral target.


Subject(s)
Betacoronavirus/physiology , DNA Topoisomerases, Type I/metabolism , RNA Viruses/metabolism , Virus Replication/physiology , Cell Line , Dengue Virus/physiology , Ebolavirus/physiology , Gene Knockout Techniques , Humans , Influenza A virus/physiology , SARS-CoV-2 , Yellow fever virus/physiology , Zika Virus/physiology
12.
Nat Commun ; 11(1): 4207, 2020 08 21.
Article in English | MEDLINE | ID: covidwho-724410

ABSTRACT

The rapid spread of coronavirus SARS-CoV-2 greatly threatens global public health but no prophylactic vaccine is available. Here, we report the generation of a replication-incompetent recombinant serotype 5 adenovirus, Ad5-S-nb2, carrying a codon-optimized gene encoding Spike protein (S). In mice and rhesus macaques, intramuscular injection with Ad5-S-nb2 elicits systemic S-specific antibody and cell-mediated immune (CMI) responses. Intranasal inoculation elicits both systemic and pulmonary antibody responses but weaker CMI response. At 30 days after a single vaccination with Ad5-S-nb2 either intramuscularly or intranasally, macaques are protected against SARS-CoV-2 challenge. A subsequent challenge reveals that macaques vaccinated with a 10-fold lower vaccine dosage (1 × 1010 viral particles) are also protected, demonstrating the effectiveness of Ad5-S-nb2 and the possibility of offering more vaccine dosages within a shorter timeframe. Thus, Ad5-S-nb2 is a promising candidate vaccine and warrants further clinical evaluation.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/administration & dosage , Adenoviridae/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Dose-Response Relationship, Immunologic , Female , HEK293 Cells , Humans , Immunity, Cellular , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Pneumonia, Viral/immunology , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/administration & dosage
13.
Cell Res ; 30(8): 670-677, 2020 08.
Article in English | MEDLINE | ID: covidwho-637104

ABSTRACT

The 2019 novel coronavirus (SARS-CoV-2) outbreak is a major challenge for public health. SARS-CoV-2 infection in human has a broad clinical spectrum ranging from mild to severe cases, with a mortality rate of ~6.4% worldwide (based on World Health Organization daily situation report). However, the dynamics of viral infection, replication and shedding are poorly understood. Here, we show that Rhesus macaques are susceptible to the infection by SARS-CoV-2. After intratracheal inoculation, the first peak of viral RNA was observed in oropharyngeal swabs one day post infection (1 d.p.i.), mainly from the input of the inoculation, while the second peak occurred at 5 d.p.i., which reflected on-site replication in the respiratory tract. Histopathological observation shows that SARS-CoV-2 infection can cause interstitial pneumonia in animals, characterized by hyperemia and edema, and infiltration of monocytes and lymphocytes in alveoli. We also identified SARS-CoV-2 RNA in respiratory tract tissues, including trachea, bronchus and lung; and viruses were also re-isolated from oropharyngeal swabs, bronchus and lung, respectively. Furthermore, we demonstrated that neutralizing antibodies generated from the primary infection could protect the Rhesus macaques from a second-round challenge by SARS-CoV-2. The non-human primate model that we established here provides a valuable platform to study SARS-CoV-2 pathogenesis and to evaluate candidate vaccines and therapeutics.


Subject(s)
Betacoronavirus/genetics , Betacoronavirus/immunology , Coronavirus Infections/pathology , Disease Models, Animal , Macaca mulatta/virology , Pneumonia, Viral/pathology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/virology , Female , Immunohistochemistry , Male , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/virology , RNA, Viral/genetics , Radiography, Thoracic , Real-Time Polymerase Chain Reaction , SARS-CoV-2 , Viral Load , Virus Replication
14.
Nature ; 584(7819): 120-124, 2020 08.
Article in English | MEDLINE | ID: covidwho-381744

ABSTRACT

An outbreak of coronavirus disease 2019 (COVID-19)1-3, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)4, has spread globally. Countermeasures are needed to treat and prevent further dissemination of the virus. Here we report the isolation of two specific human monoclonal antibodies (termed CA1 and CB6) from a patient convalescing from COVID-19. CA1 and CB6 demonstrated potent SARS-CoV-2-specific neutralization activity in vitro. In addition, CB6 inhibited infection with SARS-CoV-2 in rhesus monkeys in both prophylactic and treatment settings. We also performed structural studies, which revealed that CB6 recognizes an epitope that overlaps with angiotensin-converting enzyme 2 (ACE2)-binding sites in the SARS-CoV-2 receptor-binding domain, and thereby interferes with virus-receptor interactions by both steric hindrance and direct competition for interface residues. Our results suggest that CB6 deserves further study as a candidate for translation to the clinic.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/chemistry , Antibodies, Viral/pharmacology , Betacoronavirus/chemistry , Binding, Competitive , COVID-19 , Cell Line , Chlorocebus aethiops , Crystallization , Crystallography, X-Ray , Female , Humans , In Vitro Techniques , Macaca mulatta/immunology , Macaca mulatta/virology , Male , Models, Molecular , Neutralization Tests , Pandemics , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Protein Binding/drug effects , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Viral Load/immunology
15.
Cell ; 182(1): 50-58.e8, 2020 07 09.
Article in English | MEDLINE | ID: covidwho-343611

ABSTRACT

COVID-19 has spread worldwide since 2019 and is now a severe threat to public health. We previously identified the causative agent as a novel SARS-related coronavirus (SARS-CoV-2) that uses human angiotensin-converting enzyme 2 (hACE2) as the entry receptor. Here, we successfully developed a SARS-CoV-2 hACE2 transgenic mouse (HFH4-hACE2 in C3B6 mice) infection model. The infected mice generated typical interstitial pneumonia and pathology that were similar to those of COVID-19 patients. Viral quantification revealed the lungs as the major site of infection, although viral RNA could also be found in the eye, heart, and brain in some mice. Virus identical to SARS-CoV-2 in full-genome sequences was isolated from the infected lung and brain tissues. Last, we showed that pre-exposure to SARS-CoV-2 could protect mice from severe pneumonia. Our results show that the hACE2 mouse would be a valuable tool for testing potential vaccines and therapeutics.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/pathology , Disease Models, Animal , Mice, Transgenic , Pneumonia, Viral/pathology , Angiotensin-Converting Enzyme 2 , Animals , COVID-19 , Female , Humans , Lung Diseases, Interstitial/pathology , Lung Diseases, Interstitial/virology , Male , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Transgenic/genetics , Pandemics , Peptidyl-Dipeptidase A/genetics , SARS-CoV-2 , Viral Tropism , Weight Loss
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